Table 1:
Shown are the protein names, N-terminal sequence of the mature protein, and the penultimate residue that would be recognized and cleaved by DPP4, as annotated by Uniprot. The final column indicates whether there are multiple truncation sites available to DPP4. What YES indicates is that after the first truncation, there is another putative DPP4 site remaining on the truncated protein that may be cleaved again. Additional cleavages of the protein may further alter the functions of these molecules, and there may be differences in the function of a singly truncated protein versus a doubly (triply, etc.) truncated peptide. YES *(Serine) indicates that the protein has a second putative DPP4 truncation site, but that this second site is a Serine residue, for which DPP4 has a lower affinity. Proteins highlighted in red are newly identified putative targets of DPP4 that were not listed in a previous review that gave a more comprehensive description specifically of secreted DPP4 targets [17].
| Protein | N-term sequence | Penultimate AA (substrate) | Multiple truncation sites? | Protein | N-term sequence | Penultimate AA (substrate) | Multiple truncation sites? |
|---|---|---|---|---|---|---|---|
|
| |||||||
| CCL11 | GPASVP | P | YES (*Serine) | CXCL8/IL8 | SAKELR | A | NO |
| CCL13 | LAQPDA | A | YES | CXCL9 | TPVVRK | P | NO |
| CCL13 | QPDALN | P | YES | GCG/GLP-1 | HADGSF | A | NO |
| CCL14 | GPYHPS | P | NO | IFNL1/IL29 | GPVPTS | P | YES |
| CCL15 | AADCCT | A | NO | IFNL2/IL28A | VPVARL | P | YES |
| CCL16 | QPKVPE | P | NO | IFNL3/IL28B | VPVARL | P | YES |
| CCL2 | QPDAIN | P | YES | IFNL4 | AAPRRC | A | NO |
| CCL22 | GPYGAN | P | NO | IL10 | SPGQGT | P | NO |
| CCL23 | NPVLLD | P | NO | IL16 | SAASAS | A | YES (*Serine) |
| CCL23 | HATSAD | A | YES (*Serine) | IL17B | QPRSPK | P | YES (*Serine) |
| CCL23 | SADCCI | A | NO | IL18BP | TPVSQT | P | YES (*Serine) |
| CCL3L1 | APLAAD | P | YES | IL1A | SAPFSF | A | NO |
| CCL3L1 | LAADTP | A | NO | IL1B | APVRSL | P | NO |
| CCL4 | APMGSD | P | NO | IL1RA | RPSGRK | P | NO |
| CCL4L1 | APMGSD | P | NO | IL2 | APTSSS | P | YES (*Serine) |
| CCL5 | SPYSSD | P | YES (*Serine) | IL22 | APISSH | P | YES (*Serine) |
| CCL7 | QPVGIN | P | NO | IL23A | RAVPGG | A | YES |
| CCL8 | QPDSVS | P | YES (*Serine) | IL27 | FPRPPG | P | YES |
| CXCL10 | VPLSRT | P | YES (*Serine) | IL3 | APMTQT | P | NO |
| CXCL11 | FPMFKR | P | NO | IL5 | IPTEIP | P | NO |
| CXCL12/ SDF-1 |
KPVSLS | P | YES (*Serine) | IL6 | VPPGED | P | NO |
| CXCL2 | APLATE | P | YES | LIF | SPLPIT | P | YES |
| CXCL6 | GPVSAV | P | YES (*Serine) | NPY | YPSKPD | P | NO |